Clutch.



Patented July 9, |901.

B. H. LCKE.

C L U T C H (Application led Nov. 20, 1900.)

(No Modal.)

wnN'EssEs BY. l/

@www

TORNEYS UNITED STATES `ATENT trice.

BRADFORD I-I. LOOKE, OF DENVER, COLORADO.

CLUTCH.

SPECIFICATION formingpart of Letters Patent No. 6??,872, dated July 9, 1901. Application filed November 20, 1900. VSerial No. 37,094. (No model.)

To all whom t may con/cern:

Be it known that I, BRADFORD H. LOCKE, acitizen of the United States, residing in Denver, county of Arapahoe, State of Colorado, have invented certain new and useful Improvementsin Clutches, of which the follow ing is a specification, reference being had to the accompanying drawings, forming a part hereof.

This invention has for its object to provide an improved clutch or yielding connection which will serve to transmit the required power under all ordinary conditions of use, but will yield if the driven part of the mechanism to which itis applied is held from movement, permitting the driving part to conL tinue its movement.

The invention will be more fully described hereinafter, with reference to the accompanying drawings, in which it is illustrated as embodied in a convenient and practical form, and in which- Figure l is a View, partly in longitudinal section, of a clutch which embodies the invention. Figs. 2 and 3 are sections on the plane indicated by the line 2 2 of Fig-l, Fig. 2 representing the section as seen in the direction of the arrow on Fig. l and showing the parts in the relation which they hold when driving and Fig. 3 representing the section as seen in the opposite direction and showing the parts in the relation which they assume when the driven part is held from movement. Fig. 4 is a view similar to Fig. l, but illustrating a different relative arrangement of some of the parts.

In the several gures of the drawings the driver or driving member is sufficiently illustrated or represented by the shaft a, the direction of rotation of such driver being indicated in each case by the arrow thereon. To the driver is applied a stiff spiral spring, which is of such form as to give a comparatively large bearing or friction surface for cooperation with a cylindrical driven part or member. The relation of the spiral spring to the cylindrical driven part with which it engages frictionally is such that the spring under normal conditions is in close frictional contact with the driven part and that when the driven part is held from rotation the continued rotation of the driver expands or coni tracts the spring with reference to the driven part, according to the form of such driven part, and therefore slips with reference to such driven part, so that the driver may core` tinue to rotate. The frictional engagement of the spring with the driven part is suiiicient under normal conditions to transmit to the driven part the required power. As illus trated in Figs. l, 2, and 3, the coiled spring b is crowded into a sleeve c, which represents the driven part, such sleeve being connected in any convenient manner to the mechanism to be driven, as bya shaft d. Normally the eX- ternal diameter of the coiled spring b is somewhat greater than the internal diameter of the sleeve c, so that the spring must be crowded into the sleeve and shall have such frictional contact or engagement therewith as to trans; mit to the driven part the required power, as above stated. The spring is connected to the driver, as by a pin and in this instance is coiled in a direction opposite to the direction of rotation of the driver a, so that when the driven member c is held from rotation the continued rotation of the shaft will tend to wind the spring upon itself, contracting the diameter of the spiral and releasing the frictional engagement with the driven member o, thereby permitting the spring to slip with reference to the driven member. In the arrangement shown in Fig. 4 the cylindrical member instead of being formed as a sleeve is a cylindrical shaft c', around which the coiled spring b fits snugly, the internal diameter of the coil being normally less than the diameter of the shaft. In this case the frictional engagement of the spring, which is connected with the driver ct, as by a pin e, is sufficient under normal conditions to transmit the required power to the shaft c or driven member. The spring b' in this form of the device is coiled in the same direction as the direction of rotation of the driver, so that when the driven member is held from rotation the continued rotation of the driver expands the spring away from the driven member, releasing the frictional engagement of the spring with the driven member and permitting the spring to slip with reference to said driven member.

It will be observed in each ca se that the normal relation between the diameter of the IOO spring and the diameter of the driven part is such that the spring is in close frictional contact with the driven part and that the spring is coiled in such direction with reference to the direction of rotation of the driver that the rtendencyT of the driver is to change the diameter of the spring with reference to the driven part, so as to release the spring from frictional engagement with the driven part. Otherwise the precise construction and arrangement of parts may be varied Without departing from the spirit of the invention.

I claim as my inventiont A slipping clutch comprising a driver, a

einem BRADFORD H. LOCKE.

ln presence of A. N. JESBERA, W. B. GREELEY. 

